A sprig of dried rose hips sits atop Nels Broste's drafting table, in a classroom inside the Denver Botanic Gardens. Broste has drawn an outline on the paper in front of him, and flips back and forth between sheets of tracing paper as he tries to perfect his composition.
Connie Sayas, his instructor, walks up with some encouragement and a few tips.
"So what I like is these interesting shapes, so if this was your paper, we've got this nice jagged edge here," said Sayas.
"I also like the balance between the different textures, so we know that these rose hips are crinkled up, it will be a really nice contrast. So you want to push those textures."
Broste is not an artist by training -- he's a retired engineer -- but his sketch is spot on. He recently earned a certificate from the Denver Botanic Gardens School of Botanical Art and Illustration. He's taking this extra class, "for the fun of it."